Endoscopic ultrasound (EUS) is a minimally invasive procedure to assess the gastrointestinal (GI) tract and the organs in close proximity to it like the pancreas, biliary system and liver. A special endoscope uses high-frequency sound waves to produce detailed images of the lining and walls of your digestive tract and nearby organs.
When combined with a procedure called fine-needle aspiration, EUS allows your doctor to sample (biopsy) fluid and tissue for analysis. EUS with fine-needle aspiration can be a minimally invasive alternative to exploratory surgery.
EUS provides your doctor with more information than other imaging tests by providing detailed images of your digestive tract. Your doctor can use EUS to diagnose certain conditions that may cause abdominal pain or abnormal weight loss.
EUS is also used to evaluate known abnormalities, including lumps or lesions, which were detected at a prior endoscopy or were seen on imaging, such as a computed tomography (CT) scan or magnetic resonance imaging (MRI). EUS provides a detailed image of the lump or lesion, which can help your doctor determine its origin and help treatment decisions. EUS can be used to diagnose diseases of the pancreas, bile duct and gallbladder when other tests are inconclusive or conflicting.
You will be asked not to eat or drink anything for six to eight hours before the test. It is important for the stomach to be empty to allow the endoscopist to visualize the entire area, and to decrease the chance of vomiting during the procedure.
You may be instructed to adjust the dose of your medications or stop taking specific medications prior to the examination. All medications and dietary supplements should be discussed with your gastroenterologist since some are more important than others. If you are taking a blood-thinning medication, your gastroenterologist will determine how and when you should stop taking this prior to EUS. If you are diabetic, adjustments will be made to your morning doses of medication (tablets or insulin) because you cannot eat anything before your EUS.
You will need a friend or family member to escort you home after the examination. This is because the medications used for sedation can impair reflexes, judgment, and your ability to drive (similar to the effects of alcohol).
Prior to the endoscopy, you will be asked some questions about your medical history and the medications you are currently taking, and the results of your blood tests will be checked. The EUS procedure will also be explained in detail, and the doctor will verify that the consent form was signed.
Sedation — Before the procedure a light anaesthetic is given. You may be slightly aware of what is going on in the room, but generally you will not remember anything. A highly qualified anaesthetist and nursing team will monitor your vital signs and will keep as comfortable as possible. You are unlikely to require a general anaesthetic, however if this is the case your anaesthetist will speak to you first.
The EUS endoscope is a special flexible tube, approximately the size of a finger. It contains a lens and a light source that allows the endoscopist to view the inside of the patient’s body. It also contains a highly sophisticated ultrasound probe that helps the doctor look through the walls of the GI tract. Images are magnified on a monitor so that even very small details and changes can be seen. The endoscope also contains channels that allow the endoscopist to do fine needle aspiration (biopsies) and introduce or withdraw fluid, air, or other instruments.
One you are sedated, the scope is inserted through the mouth and advanced into the GI tract. It is placed near the area of interest, and then thorough examination is performed. If required and safe to do so then a fine needle aspiration can be obtained. The procedure takes about 30 to 40 min.
After EUS, you will be monitored while the sedative medications wear off. The most common discomfort after the examination is a feeling of bloating as a result of the air introduced during the examination. This usually resolves quickly. Some people also have a mild sore throat. Most people are able to drink clear liquids shortly after the examination.
The endoscopist can usually tell the patient the results of their examination right away. If biopsies were taken, the tissue will need to be sent to a lab for analysis.
EUS is generally safe when performed by an experienced and expert health care team. Your gastroenterologist will discuss with you the risk of complications from EUS. Risks are rare and may include:
- Bleeding
- Tearing (perforation) of the intestinal wall or throat
- Infection
- Pancreatitis, if fine-needle aspiration of the pancreas is done
If you have any of the following symptoms soon after the procedure
- Severe abdominal pain (not just gas cramps)
- A firm, distended abdomen
- Vomiting
- Fever or chills
- Difficulty in swallowing or a severe sore throat
You should contact the hospital or your doctor’s rooms immediately using the contact details.